Q: What was the underlying lesson to be learned from the opening excerpt from George Orwell's (then) futuristic book 1984?

A: Personification - "If the Party could thrust its hand into the past and say this or that even, it never happened?that, surely, was more terrifying than mere torture and death,"? (Orwell 126).
Orwell uses personification to give life to the story. [ [ In this quote, he gives life to the Party by saying it could thrust its hand into the past, which is obviously not something that can be done. ]